SOLUTION: It is desired to draw off a part of 10 gallons of 30% solution of alcohol and to replace it by pure alcohol so as to produce a 50% solution. How many gallons should be drawn off?

Question 1203496: It is desired to draw off a part of 10 gallons of 30% solution of alcohol and to replace it by pure alcohol so as to produce a 50% solution. How many gallons should be drawn off?
Answer by josgarithmetic(39617) (Show Source): You can put this solution on YOUR website!
Helpful guide here: https://www.algebra.com/my/drain-and-replace-antifreeze.lesson?content_action=show_dev
https://www.algebra.com/my/drain-and-replace-antifreeze.lesson?content_action=show_dev

This method may be approximate, not perfectly accurate:

Draw off some v gallons of the 30% alcohol.
Replace with v gallons of the 100% alcohol.
Want 50% alcohol result.

-----------all computations have been postponed to here.
Now just compute v.
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